Pollutant Concentrations

Air quality readings will be available hourly from 7am to 11pm. Air quality readings from 12am to 6am will be made available at 7am on the same day.

Readings on 20 Nov 2014

View reading for:

Region

24-hr Sulphur dioxide(µg/m3)

24-hr PM10(µg/m3)

1-hr Nitrogen dioxide(µg/m3)a

8-hr Ozone(µg/m3)

8-hr Carbon monoxide(mg/m3)

24-hr PM2.5(µg/m3)

North

5(3)

21(21)

54(-)

14(6)

0.4(4)

10(41)

South

6(4)

18(18)

47(-)

13(5)

0.6(6)

9(39)

East

3(2)

17(17)

19(-)

18(8)

0.4(4)

10(42)

West

3(2)

19(19)

20(-)

22(9)

0.5(5)

9(36)

Central

7(4)

16(16)

54(-)

22(9)

0.6(6)

8(34)

1-hr PM2.5 (µg/m3)b Readings on 20 Nov 2014

View reading for:

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

North

14

6

3

7

3

4

7

7

11

7

7

9

South

3

2

1

3

4

6

5

6

4

11

9

17

East

5

9

23

16

26

14

7

9

7

12

13

8

West

13

10

6

4

4

4

3

2

6

9

7

8

Central

4

3

3

8

5

8

4

11

8

4

4

5

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

North

13

12

8

6

11

8

4

16

20

29

17

-

South

16

21

17

18

16

9

7

18

4

10

17

-

East

6

5

7

11

10

11

7

11

5

8

8

-

West

7

10

15

16

8

16

18

11

10

13

5

-

Central

5

10

7

10

19

8

6

12

13

21

18

-

Note:a Sub-index for nitrogen dioxide is reported only when the 1-hr concentration equals or exceeds 1130 µg/m3.

b There is no sub-index for 1-hr PM2.5.

3-hr PSI Readings from 1am to 12am on
20 Nov 2014

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

3-hr PSI

27

24

29

29

32

32

29

27

27

32

33

36

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

3-hr PSI

37

43

44

48

49

49

44

45

45

53

52

-

Hourly updates of 3-hr PSI readings are provided from 7am to 11pm. The 3-hr PSI readings from 12am to 6am will be made available at 7am on the same day. The 3-hr PSI readings are calculated based on PM2.5 concentrations only.